The present invention relates to metal-oxide-semiconductor field-effect transistors (MOSFET), and more specifically, to fin-type field-effect transistors (finFET).
The MOSFET is a transistor used for amplifying or switching electronic signals. The MOSFET has a source, a drain, and a metal oxide gate electrode. The metal gate is electrically insulated from the main semiconductor n-channel or p-channel by a thin layer of insulating material, for example, silicon dioxide or glass, which makes the input resistance of the MOSFET relatively high. The gate voltage controls whether the path from drain to source is an open circuit (“off”) or a resistive path (“on”).
The finFET is a type of MOSFET. The finFET is a double-gate or a tri-gate semiconductor on bulk Si or SOI (semiconductor on oxide, e.g., silicon-on-oxide) device that mitigates the effects of short channels and reduces drain-induced barrier lowering. The “fin” refers to the narrow channel between source and drain regions. A thin insulating oxide layer on either side of the fin separates the fin from the gate.
Size reduction of finFETs, including reduction of the gate length and gate oxide thickness, enables improvement in speed, performance, density, and cost per unit function of integrated circuits. Transistor designs utilizing raised source/drain regions having one or more raised channel regions (i.e., fins) interconnecting the source and drain regions. A gate is formed by depositing a conductive layer over and/or adjacent to the fins. FinFET designs provide better scalability as design requirements shrink and also provide better short-channel control.